Device and method for controlling drying of laundry in drum type washing machine

ABSTRACT

Device and method for controlling drying of laundry in a drum type washing machine, the device including a motor for rotating a drum, a motor sensing part for detecting rotation speed of the motor, and a controlling part for controlling the motor sensing part to detect the rotation speed of the motor during a spinning time period, and setting a drying cycle time period according to the detected rotation speed, thereby drying laundry, effectively.

[0001] This application claims the benefit of the Korean Application No.P2002-0073878 filed on Nov. 26, 2002, which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to drum type washing machines, andmore particularly, to device and method for controlling drying oflaundry in a drum type washing machine.

[0004] 2. Background of the Related Art

[0005] Referring to FIGS. 1 and 2, a related art washing and dryingmachine is provided with a door 2 on a front part of a body 1, a tub 3in the body 1, a drum 6 in the tub 3 for rotating upon receiving adriving force from a motor through a belt 5, a gasket 7 between a frontpart of the tub 3 and the body 1 for damping and packing when the drum 6rotates, a detergent box 9 in an upper part of an inside of the body 1connected to the tub 3 through a water supply hose 8, a discharge pump10 and a discharge hose 11 in a lower part of an outside of the tub 3,and a washing heater 12 in a lower of an inside of the tub 3.

[0006] The related art washing and drying machine is also provided witha fan 13 in the upper part of the body 1, wherein the fan 13 and thegasket 7 are connected with an air duct 14 such that the fan blows airto insides of the tub 3 and the drum 6, a drying heater 15 in the airduct for heating the air blown through the air duct, a condensing duct16 connected between the fan 13 and the tub 3 for serving as an airpassage, and a condensed water pipe 17 and a water inlet 18 at one sideof the body 1 for supplying condensed water into the condensing duct 16to cool down circulating air with cold water.

[0007] Therefore, when a user opens the door 2, introduces laundry intothe drum 6, and selects an operation button, washing water is introducedinto the tub 3 through the detergent box 9 guided by the water supplyhose 8, until the water fills the tub 3 and the drum 6 in the tub 3 to arequired level 6.

[0008] When the washing water is filled in the tub 3 and the drum 6 tothe required level 6, the water supply is stopped, the motor 4 rotatesin regular/reverse directions, and a driving power of the motor 4 istransmitted to the drum 6 through a belt 5, to rotate the drum 6 in theregular/reverse directions at regular intervals, when the laundry ismade fluid by lifts (not shown) on an inside circumferential surface ofthe drum 6, to progress washing by a friction force between the laundryand the drum, and a dissolving capability of the detergent.

[0009] If the user selects a water temperature before starting thewashing, the washing water in the drum 6 is heated to the selectedtemperature as the washing heater 12 generates heat.

[0010] Upon finishing a washing cycle, the discharge valve 10 is opened,to discharge used washing water to an outside of the washing machinethrough the discharge hose 11, and upon finishing the discharge ofwater, a rinsing cycle is started in the same operation as the washingcycle.

[0011] After a rinsing process is repeated for a preset times, aspinning cycle is started. Upon finishing the spinning cycle, the drum 6is rotated in regular/reverse directions to make the laundry fluid thesame as the washing cycle, and the fan 13 is put into operation to blowair into the tub 3 and the drum 6. At this time, the drying heater 15 inthe air duct 14 also generates heat, to heat the air blown into the tub3 and the drum 6. According to this, moisture in the laundry is removedby hot air introduced into the drum 6. The hot air introduced into thedrum 6 circulates back to the fan 13 through the condensing duct 16connected between the fan and the tub 3.

[0012] However, in the related art washing and drying machine, since theuser carries out the drying cycle for a preset time period in the dryingcycle, the drying cycle is progressed regardless of a quantity of thelaundry, or a moisture content of the laundry, to cause problems in thatthe laundry is dried insufficiently, or power is consumed, excessively.

SUMMARY OF THE INVENTION

[0013] Accordingly, the present invention is directed to device andmethod for controlling drying of laundry in a drum type washing machinethat substantially obviates one or more of the problems due tolimitations and disadvantages of the related art.

[0014] An object of the present invention is to provide device andmethod for controlling drying of laundry in a drum type washing machine,in which laundry can be dried, effectively.

[0015] Additional features and advantages of the invention will be setforth in the description which follows, and in part will be apparent tothose having ordinary skill in the art upon examination of the followingor may be learned from practice of the invention. The objectives andother advantages of the invention will be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

[0016] To achieve these objects and other advantages and in accordancewith the purpose of the present invention, as embodied and broadlydescribed herein, the device for controlling drying of laundry in a drumtype washing machine includes a motor for rotating a drum, a motorsensing part for detecting rotation speed of the motor, and acontrolling part for controlling the motor sensing part to detect therotation speed of the motor during a spinning time period, and setting adrying cycle time period according to the detected rotation speed.

[0017] The controlling part compares the detected rotation speed topreset rotation speeds. In this instance, the controlling part comparesthe detected maximum value of the rotation speed to the set rotationspeeds in an order of a maximum value thereof to a minimum valuethereof, and the controlling part detects the set rotation speed thesame with a maximum value of the detected rotation speed from the setrotation speeds, and determines the drying time period relevant to thedetected set rotation speed as the drying cycle time period.

[0018] The controlling part sets the drying cycle time period the longeras the detected rotation speed is the lower, and vice versa.

[0019] In other aspect of the present invention, there is provided adevice for controlling drying of laundry in a drum type washing machineincluding a motor for rotating a drum, a motor sensing part fordetecting rotation speed of the motor, a fan for blowing air into thedrum, a drying heater for heating the air from the fan, and acontrolling part for controlling the motor sensing part to detect therotation speed of the motor during a spinning time period, and setting adrying cycle time period according to an amount of laundry and thedetected rotation speed.

[0020] The controlling part compares the detected maximum value of therotation speed to the set rotation speeds in an order of a maximum valuethereof to a minimum value thereof. The controlling part determines thedrying time period relevant to the set rotation speed as the dryingcycle time period if the maximum value of the detected rotation speed isequal to or higher than the set rotation speed.

[0021] The controlling part sets the drying cycle time period thelonger, as the amount of the laundry is the greater.

[0022] In another aspect of the present invention, there is provided amethod for controlling dying of laundry in a drum type washing machine,including the steps of (a) detecting a rotation speed of a motor duringa spinning cycle, (b) setting a drying cycle time period according tothe detected rotation speed, and (c) drying the laundry for the setdrying cycle time period.

[0023] The step of setting a drying cycle time period according to thedetected rotation speed includes the step of comparing the detectedrotation speed to set rotation speeds. The step of setting a dryingcycle time period according to the detected rotation speed furtherincludes the steps of detecting one of the set rotation speeds identicalto a maximum speed of the detected rotation speed, and determining adrying time period relevant to the detected set rotation speed as thedrying cycle time period.

[0024] The step of setting a drying cycle time period according to thedetected rotation speed further includes the steps of comparing themaximum value of the detected rotation speed to the set rotation speedsin an order of a maximum value to a minimum value. The step of setting adrying cycle time period according to the detected rotation speedfurther includes the steps of determining the drying time periodrelevant to the set rotation speed as the drying cycle time period ifthe maximum value of the detected rotation speed is equal to or higherthan the set rotation speed.

[0025] The step of setting a drying cycle time period according to thedetected rotation speed further includes the steps of setting the dryingcycle time period the longer as the detected rotation speed is thelower, and vice versa.

[0026] In further aspect of the present invention, there is provided amethod for controlling dying of laundry in a drum type washing machine,including the steps of (a) detecting an amount of the laundry, (b)detecting a rotation speed of a motor during a spinning cycle, (c)setting a drying cycle time period according to the detected amount ofthe laundry and the detected rotation speed, and (d) drying the laundryfor the set drying cycle time period.

[0027] The step of setting a drying cycle time period according to thedetected amount of the laundry and the detected rotation speed includesthe steps of setting a drying time period according to the amount oflaundry, and adjusting the set drying time period according to therotation speed. The step of setting a drying time period according tothe amount of laundry includes the step of setting the drying cycle timeperiod the longer as the amount of laundry is the grater, and viceversa. The step of adjusting the set drying time period according to therotation speed includes the step of setting the drying cycle time periodthe longer as the as the maximum value of the detected rotation speed isthe smaller, and vice versa.

[0028] It is to be understood that both the foregoing description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention claimed.

BRIEF DESCRITPION OF THE DRAWINGS

[0029] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this application, illustrate embodiment(s) of theinvention and together with the description serve to explain theprinciple of the invention. In the drawings;

[0030]FIG. 1 illustrates a longitudinal section of key parts of arelated art drum type washing machine;

[0031]FIG. 2 illustrates a section of key parts across a line A-A inFIG. 1;

[0032]FIG. 3 illustrates a device for controlling drying of laundry in adrum type washing machine in accordance with a preferred embodiment ofthe present invention; and

[0033]FIG. 4 illustrates a flow chart showing the steps of a method forcontrolling drying of laundry in accordance with a preferred embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0034] Reference will now be made in detail to the preferred embodimentsof the present invention, examples of which are illustrated in theaccompanying drawings. FIG. 3 illustrates a device for controllingdrying of laundry in a drum type washing machine in accordance with apreferred embodiment of the present invention.

[0035] Referring to FIG. 3, the device for controlling drying of laundryin a drum type washing machine includes a motor 110 for rotating a drum(see reference symbol 6 in FIG. 1), a motor sensing part 120 fordetecting a rotation speeds of the motor 110, a fan 150 for blowing airinto the drum, a drying heater 140 for heating air from the fan 150, anda controlling part 130 for automatic control of a laundry drying timeperiod according to a rotation power of the motor 110.

[0036] The operation of, and a method for controlling drying of laundryin a drum type washing machine in accordance with a preferred embodimentof the present invention will be described, with reference to FIG. 4.

[0037] When a user introduces laundry into a drum, and selects a washingmode or a washing course the user desires, the controlling part 130rotates the drum in regular/reverse direction to detect an amount of thelaundry. In this instance, the controlling part 130 detects the amountof laundry with reference to a load on the motor 110 at the time ofregular/reverse direction rotation of the drum. Then, the controllingpart 130 determines a water level, a washing time period, a rinsing timeperiod and a number of rinsing, a spinning time period according to theamount of laundry. The controlling part 130 also can set a drying timeperiod according to the amount of laundry, automatically. Then, thecontrolling part supplies water to the drum until a determined waterlevel is reached, together with detergent.

[0038] When water is filled up to a determined water level, thecontrolling part 130 puts the motor 130 into operation for carrying outthe washing cycle according to the washing mode the user selects. (S11).A rotating power of the motor 110 is transmitted to the drum through abelt, to rotate the drum at a regular frequency. The laundry is washedowing to friction with the drum, and the impact of fall after liftedtogether with water and detergent inside of the drum.

[0039] Then, if the washing cycle is finished, used water is dischargedto an outside of the washing machine, and the rinsing cycle is startedafter water is supplied to the drum again. (S12). The rinsing cycle isrepeated for a determined number of times according to the washing modeselected by the user.

[0040] The spinning cycle is started if the rinsing cycle is finished.In the spinning cycle, rotation (or RPM) power and time period of themotor 110 may be set by the user, or by the controlling part 130according to an amount or kinds of the laundry, automatically. While thespinning cycle is progressed, the motor sensing part 120 detects arotation speed of the motor 110, and the controlling part 130 stores it.(S13).

[0041] Then, after finishing the spinning cycle, the controlling part130 determines if the user selects the drying cycle. (S14). If it isdetermined that the user selects no drying cycle, the controlling part130 finishes the operation of the washing machine. Opposite to this, ifit is determined that the user selects the drying cycle, the controllingpart 130 compares a maximum value of the stored rotation speed to afirst set rotation speed. (S15).

[0042] The first set rotation speed, set in advance and stored in thecontrolling part 130, is for an example, 1400 RPM. If the motor 110rotates 140 RPM, the controlling part 130, determining that extractionof water from the laundry is enough, sets an appropriate drying cycle.In other words, if the maximum value of the rotation speed is equal toor higher than the first set rotation speed, the controlling part 130sets a drying cycle time period to a first drying time period T1. (S16).Then, the controlling part 130 progresses the drying cycle for the firstdrying time period T1. (S23). In this instance, the controlling part 130controls the fan 150 to blow air, and controls the drying heater 140, toheat the air.

[0043] If the maximum value of the rotation speed is lower than thefirst set rotation speed, the controlling part 130 compares the rotationspeed with a second set rotation speed. (S17). The second set rotationspeed is a value lower than the first set rotation speed, for anexample, 1200 RPM. If the maximum value of the rotation speed is equalto, or higher than the second set rotation speed, the controlling part130 sets the drying cycle time period to a second drying time period T2.(S18). The second drying time period T2 is longer than the first dryingtime period (T2). In other words, the controlling part 130, determiningthat the extraction of water from the laundry is not enough if therotation speed of the motor 110 is lower than the first set rotationspeed, sets the drying cycle time period longer than the first dryingtime period T1. Then, the controlling part 130 progresses the dryingcycle for the second drying time period T2. (S23).

[0044] If the maximum value of the rotation speed is lower than thesecond set rotation speed, the controlling part 130 compares therotation speed to a third set rotation speed. (S19). The third setrotation speed is lower than the first, or second set rotation speed,for an example, 1000 RPM. If the maximum rotation value is equal to, orhigher than the third set rotation speed, the controlling part 130 setsthe drying cycle time period to the third drying time period T3. (S20).The third drying time period T3 is longer than the first or seconddrying time period T1 or T2. Then, the controlling part 130 progressesthe drying cycle for the third drying time period T3. (S23).

[0045] If the maximum value of the rotation speed is lower than thethird set rotation speed, the controlling part 130 compares the rotationspeed to a fourth set rotation speed. (S21). The fourth set rotationspeed is lower than the first, second, or third set rotation speed, foran example, 800 RPM. If the maximum rotation value is equal to, orhigher than the fourth set rotation speed, the controlling part 130 setsthe drying cycle time period to the fourth drying time period T4. (S20).The fourth drying time period T4 is longer than the first, second, orthird drying time period T1, T2, or T3. If the rotation speed of themotor 110 is lower than the first, second, or third set rotation speed,the controlling part 130 set the drying cycle time period longer thanthe first, second, third time period T1, T2, or T3. Then, thecontrolling part 130 progresses the drying cycle for the third dryingtime period T4. (S23).

[0046] The first, second, third, and fourth set rotation speeds, and thefirst, second, third, and fourth drying time periods T1, T2, T3, and T4are value stored in the controlling part 130. The set rotation speeds,and the drying time periods may be set in more than five levels.Moreover, the first, second, third, and fourth drying time periods T1,T2, T3, and T4 may be set not only according to the set rotation speeds,but also according to an amount of the laundry. In other words, afterbeing set according to the amount of laundry detected before the washingcycle S11, the drying cycle time period may be adjusted according to therotation speed of the motor 110 stored in the spinning cycle,automatically.

[0047] As has been described, the device and method for controllingdrying of laundry in a drum type washing machine of the presentinvention has the following advantages.

[0048] Since the drying time period is adjusted according to a rotationspeed of the washing motor in the spinning cycle, the drying cycle timeperiod can be adjusted according to a level of water extraction from thelaundry. According to this, waste of power caused by insufficient, orexcessive drying of the laundry can be reduced.

[0049] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A device for controlling drying of laundry in adrum type washing machine comprising: a motor for rotating a drum; amotor sensing part for detecting rotation speed of the motor; and acontrolling part for controlling the motor sensing part to detect therotation speed of the motor during a spinning time period, and setting adrying cycle time period according to the detected rotation speed. 2.The device as claimed in claim 1, wherein the controlling part comparesthe detected rotation speed to preset rotation speeds.
 3. The device asclaimed in claim 2, wherein the controlling part has drying time periodsrelevant to the set rotation speeds stored therein.
 4. The device asclaimed in claim 2, wherein the controlling part detects the setrotation speed the same with a maximum value of the detected rotationspeed from the set rotation speeds, and determines the drying timeperiod relevant to the detected set rotation speed as the drying cycletime period.
 5. The device as claimed in claim 2, wherein thecontrolling part compares the detected maximum value of the rotationspeed to the set rotation speeds in an order of a maximum value thereofto a minimum value thereof.
 6. The device as claimed in claim 1, whereinthe controlling part sets the drying cycle time period the longer as thedetected rotation speed is the lower, and vice versa.
 7. A device forcontrolling drying of laundry in a drum type washing machine comprising:a motor for rotating a drum; a motor sensing part for detecting rotationspeed of the motor; a fan for blowing air into the drum; a drying heaterfor heating the air from the fan; and a controlling part for controllingthe motor sensing part to detect the rotation speed of the motor duringa spinning time period, and setting a drying cycle time period accordingto an amount of laundry and the detected rotation speed.
 8. The deviceas claimed in claim 7, wherein the controlling part compares thedetected maximum value of the rotation speed to the set rotation speedsin an order of a maximum value thereof to a minimum value thereof. 9.The device as claimed in claim 8, wherein the controlling partdetermines the drying time period relevant to the set rotation speed asthe drying cycle time period if the maximum value of the detectedrotation speed is equal to or higher than the set rotation speed. 10.The device as claimed in claim 7, wherein the controlling part sets thedrying cycle time period the longer as the amount of the laundry is thegreater.
 11. A method for controlling dying of laundry in a drum typewashing machine, comprising the steps of: (a) detecting a rotation speedof a motor during a spinning cycle; (b) setting a drying cycle timeperiod according to the detected rotation speed; and (c) drying thelaundry for the set drying cycle time period.
 12. The method as claimedin claim 11, wherein the step of setting a drying cycle time periodaccording to the detected rotation speed includes the step of comparingthe detected rotation speed to set rotation speeds.
 13. The method asclaimed in claim 12, wherein the step of setting a drying cycle timeperiod according to the detected rotation speed further includes thesteps of, detecting one of the set rotation speeds identical to amaximum speed of the detected rotation speed, and determining a dryingtime period relevant to the detected set rotation speed as the dryingcycle time period.
 14. The method as claimed in claim 12, wherein thestep of setting a drying cycle time period according to the detectedrotation speed further includes the steps of, comparing the maximumvalue of the detected rotation speed to the set rotation speeds in anorder of a maximum value to a minimum value.
 15. The method as claimedin claim 14, wherein the step of setting a drying cycle time periodaccording to the detected rotation speed further includes the steps of;determining the drying time period relevant to the set rotation speed asthe drying cycle time period if the maximum value of the detectedrotation speed is equal to or higher than the set rotation speed. 16.The method as claimed in claim 11, wherein the step of setting a dryingcycle time period according to the detected rotation speed furtherincludes the steps of; setting the drying cycle time period the longeras the detected rotation speed is the lower, and vice versa.
 17. Amethod for controlling dying of laundry in a drum type washing machine,comprising the steps of: (a) detecting an amount of the laundry; (b)detecting a rotation speed of a motor during a spinning cycle; (c)setting a drying cycle time period according to the detected amount ofthe laundry and the detected rotation speed; and (d) drying the laundryfor the set drying cycle time period.
 18. The method as claimed in claim11, wherein the step of setting a drying cycle time period according tothe detected amount of the laundry and the detected rotation speedincludes the steps of; setting a drying time period according to theamount of laundry, and adjusting the set drying time period according tothe rotation speed.
 19. The method as claimed in claim 18, wherein thestep of setting a drying time period according to the amount of laundryincludes the step of; setting the drying cycle time period the longer asthe amount of laundry is the grater, and vice versa.
 20. The method asclaimed in claim 18, wherein the step of adjusting the set drying timeperiod according to the rotation speed includes the step of; setting thedrying cycle time period the longer as the as the maximum value of thedetected rotation speed is the smaller, and vice versa.